Differential pressure control valve



Sept. 28, 1954 J. w. FARRELL DIFFERENTIAL PRESSURE CONTROL VALVE 2 sheds-sheet 1 Filed May 7, 1955 Sept. 28, 1954 1 W, FARRELL ZQQ DIFFERENTIAL PRESSURE CONTROL VALVE Filed May 7, 1955 2 Sheets-Sheet 2 l INVENTOR.

JA//V #t/W6@ Z Patented Sept. 28, 1954 UNITE-D STATES PATENTv OFFICE (Granted under'Title 35, U. S. Code (1952),

sec. 266) The .invention described herein-may be manufactured and used by or for the Government for governmental purposes without payment; to me ofr yany royalty thereon.

This invention relates-to differential pressure control valves, and more particularly to hydraulic..

valves which can be used in groups tocontrol and manipulate diierent hydraulic pressures. simultaneously and automaticallyon demand` of a.

single master control valve.

In any hydraulic pressure. requirement such.

as for the static testing of an airplane-prede.- termined relative loads .are applied to. different parts of structures by Ameans ofA hydraulically operated load-strutsY or jacks and these. tests often require about to v20 different hydraulic pressures. It is necessarygwith existing .equipment, to provide an operatorfcr each relative pressure to control and regulateveach commonly connected group of struts or jacks.r Inorder to apply a predetermined relative increment 'of the tota-1 ultimate load, each operator controls the application of the relative part of the load associated With his group of load struts by manual regulation, determined by the use of a valve and pressuregauge, and the actions of .all of the oper-X ators should be simultaneous in both loading and unloading the struts.

verse load distributions do result.

However, it yoften happens' that the various operators are unable tov attain' the necessary coordination, and therefore ad-- An object of myimproved hydraulic valve is to improve the accuracy and control of such a pressure system by having all pressures automatically controlled by sensing .devices Which'follow a single demand system.

Under the preview of my invention, each of my draulic pressure 'to the inlet o-r pressure fluidl supply'conduits for each of ymy improve'dfvalves and these valves in turn automaticallyregulate the pressure delivered fromthe 'pressure -lluidn` delivery conduits of the valves tothe load-struts' or jacks, each strut therefor receivingnitsirelative proportional pressure-ratio.`

This system of operatingall.ofthe'improved hydraulic valves from 'one' pressurerisimadeapossible by the principle' cti-utilizing;'differential areas at the intake and outletfsides-.of theihys:

drauliclvalves,;and the effective relative:areas.;

offthezva'lve are lad-justablelto attainA any desired' 2 ratio of control pressure to delivery pressure, these areas and ratios remaining constant during the test. The areas are variable for other tests by the substitution of certain predetermined sizes of differential pressure control selector-cylinder, removably or replaceably attached to the ends of the valves proper. Each valve or control device, When in use vis adjusted to apply a speciiic ratio of control pressure in opposition to its inlet pressure. Since the pressure fluid Will exert the same force on both sides of the valve when it is in closed position but the areas that the pressure and a'll of the' hydraulic valves will operate 'simultaneouslyt'o applyfa true predetermined relative load distribution tothe structure being tested.

A further object is the provision of a main differential hydrauliclpressure-control valve having predetermined 'differential 'pressure areas and an auxiliary actuator including a .piston with an enclosing auxiliary cylinder 'in communication withy the delivery pressurevarea above the piston with 'an actuator movable by the pistonto assist in the closing of the main valve, whereby auxiliary cylinders or' dile'i'ent diameters may be substituted to changeA the relative moving pressure ofv the'actua'tor on the main valve.

A further object is the provision of a difierential pressure control valve having predetermined operative pressure areasy at opposite ends with one area in communication with a predetermined supply pressure and vthe other area in communication With the relative delivery pressure to control fiuid delivery proportional to the ratio between the supply and delivery pressures, and an auxiliary pressure actuator device having a cylinder and piston with a `predetermined pressure area in .communication withthe delivery pressure chamber, removably associated Withthe valve to supplement the operative delivery pressure area of said valve.

A further object is the provisionofa differential .pressurecontrol valve having a cylinder formed with a .pressure iluidsupply'chamber'at areas at its loppositeiendsand pressure operated piston valvey meansor controlling the pressure delivery' to 'the' deliveryl pressure chamberincludx ingia pressureiluidsupply conduit in communica-'A v tion with the delivery pressure chamber and a valve seat between the fluid delivery conduit and the delivery pressure chamber, together with sleeve valve surrounding the piston valve seatable on seat and having a predetermined operative differential pressure areas in communication at both sides in communication with said delivery pressure, said cylinder having an exhaust ccnduit intermediate the piston sleeve valve diicr ential pressure areas, adapted to vent the delivery prY sure chamber upon unseating of the valve, and an auxiliary diilferential pre re actuator means removably connected to the cylinder for moving the piston valve toward closed position comprising an aur i( pressure cylinder removconneoted to the casmg having a piston t`r *.in formed with a predetermined pressure and means ior actuating tle piston toward the pressure supply chamber to close the supply, and means for ntroducing pressure iluid from the pressure delivery chamber into auxiliary cylinder above the piston, to cause ac tuaticn or the piston valve in addition to the on the piston valve in the said delivery pressure chamber.

A further object of the invention includes means for admitting the delivery pressure fluid directly to the piston sleeve valve seat incident to movement or the piston valve toward the pres'- sure fluid supply chamber, for admitting the pressure iuid from the delivery pressure chaiL ber to the seat to accelerate the unseating of the piston sleeve valve and accelerate the reduction or" pressure in the supply conduit.

it further object is the use oi O rings carried by the piston valve between the piston sleeve valve and said piston Valve and between said piston valve and the casing, adapted to be uncovered by relative movement of the piston valve, and serrated back up rings or washers means located behind the O ring means for admitting pressure iiuid under the said O ring incident to the uncovering of the same by relative movement between the piston valve and piston sleeve valve to relieve pressure trapped under the O ring tending to dispiace the O rings from their receiving recesses.

Other objects and advantages of my invention will become more apparent from the following description and the accompanying drawings in which like reference characters refer to like parts in the several figures.

Drawings Fig. l is a central longitudinal sectional View taken through the center one of my improved differential pressure control valves incorporating my invention, illustrating the same in initial or pressure fluid delivery position, showing the incorporation of tivo oi the interchangeable control devices for varying the eilective ratio of the dit ferential pressure control areas, intermediate parts being broken away and the valve foreshortened for convenience.

2 is a fragmentary sectional view, somewhat similar to Fig. l, but illustrating the piston valve shifted to pressure fluid supply cut off or static position, such as when the piston valve is in equilibrium, part of the removable or change able differential pressure area control cylinders being shown in elevation.

Fig. 3 is a fragmentary elevation view of the differential pressure control device shown in section in Figs. l and 2, the right hand portion being broken away and shown in section. The piston valve and piston sleeve valve members being shown in their exhaust position for relieving the delivery pressure to the load applying jacks when this pressure exceeds the predetermir ed ratio of the delivery pressure to the supply pressure, either because of overload or reduction of the supply pressure.

`Elig. 4 is a detail perspective view of one ci the rubber 0 rings and its associated baclr up ring which is employed between the reduced extension of the piston Valve on which the piston sleeve valve is mounted and the interior of the piston sleeve valve, and also employed between 'the pressure fluid supply cut off plug valve its accommodating valve socket in the piston valve, for relieving the pressure back of the O rings prior to and after their complete unccverage.

Fig. 5 is a somewhat schematic diagram illustrating a simple test unit employing a plurality oit' pressure applying struts or jacks, each strut havn ing one of my improved automatic differential pressure control valves operatively connected thereto, together with a master control valve for supplying any predetermined initial, supply pressure to the diilerential pressure control devices.

Referring more particularly to Fig. l, my inin proved adjustable differential pressure control valve comprises a main elongated casing or bloei; i having any desired exterior shape, such as cylindrical or rectangular. The casing l is bored longitudinally to provide a main cylinder il which concentrically enlarged at 3 and at its opposite end, and threaded at 3a and la for receiving the end closure means or plugs 5 and 6.

A pressure fluid supply conduit l is in casing l in communication with the main cyan" der 2 at its pressure iluid supply or inlet end adjacent the end clos-re plug 5, the conduit 'i being threaded to receive a pressure uid .upnl conduit la adapted to be connected to a su table pressure source such as lb, with a master control pressure regulating valve euch as cated at 'le (as seen in Fig. 5) interp between. The counter-bored or enlarged tion l at the other end of the cylinder is o nected with a pressure fluid exhaust conduit formed in the block l and threaded to receive au exhaust or pressure duid return conduit ila .tor conveying the exhaust pressure luid back to the fluid supply reservoir lb associated with the pump lle and forming the initial uid pressure supply or source.

The casing or block I is formed with a pressure uid delivery conduit 3 located adjacent the ei;-1 haust conduit 8 and intermediate the exhau conduit 8 and the pressure luid supply conduit l', the exhaust or return conduit il being 'threaded to receive a pressure fluid delivery conduit or pipe Qa adapted to be connected at its other end to one (or more) of the load struts or hydraulic jacks lo.

The jacks lll are conventional and comprise a main cylinder of some predetermined size relative to the predetermined delivery pressure ratio, each having a piston jack member il tl adapted for suitable connection. te orcs y ber (not shown) having suitable spaced conne-ov tions to the part of the aircraft which is to stressed by the applied testing pressures, by cr:- tension of the jack member or members under the applied diiierential pressures.

The irme-i1: end of the end closure plug member S is beveled substantially as shown in Figs. 1 to 3 to provide a t valve seat I2 fora piston generally at I3.

The plug closure v5 is :providedwith a threaded sleeve valve indicated; i

axial bore Ill whichzadjustably receives a plug valve supporting standard I5 extending into the cylinder 2 having a threaded-socket into which is mounted a pressure fluid inlet plug valve head it having radial fluid inlet slots Il with their bottoms inclining outwardly1 and rearwardly fromthe outer end ofthe valve. An O ring seal I8= is interposedibetween the standard-'I5 and the boreV I4 to prevent leakage.

A piston valve I 9 isreciprocatably mounted within the cylinder 2, preferably having a loose slidingiit, this piston valve having a plug valveyseat or socket 2@ for reception of the plug valve head placement of the O ring 2i from the end of ther wall of the valve socket Zil as shown in Fig. l.

The piston valve I9 is formed with a fluid conduit 23 extending axially inwardy from the base of the plug valve recess'Z, with laterally or radially extending fluid conduits 2li extending therefromv tothe outer surface of the piston valvefsubstantially as-shown. An O ring iluid pressure seal 25.

is provided on the piston valve I9 intermediate the lateral passages -2llzand the valve socketed or pressude fluid supply end thereof, in a suitabhr provided annular groove in itsfouter wall.

The piston valve I9 is formed with a second set of radial pressure fluid delivery passages 2S extending inwardly from the outer surface thereof, with their inner ends in communication with a central passage 2'I through the piston valve to the opposite end thereof. on the, piston valve I9, spaced from the voutlet ends of the passages 26 `toward the said opposite end of the piston valve, sealing thek space extending therefrom A second 0 ring seal 27d is provided between the two sets of radial passagesr 24 and 2tl-y and the pressure fluid delivery conduit 9, the other O ring seal 25 seals the spacejust` re ferred to from the pressureiiuid supply l,conduit l.

Just beyond the lO ring seal 2'I'a .the piston valve is stepped down in diameter to, provide a spring seat 28 forone end of a coilspring 29 surrounding a reduced stem portion or axial extension 3i! terminating in an end flange or head SI, the other end of theispring 29 engaging a spring seat 23a on the inner end of the piston sleeve valve I3. A third set of radial passages f 32 connects the central bore 'Ir with the space between the adjacent endscf the piston sleeve valve I3 and piston valve body l!! for fluid communication between the bore 2l andthe pres-Y sure liuid delivery conduit 9 at all times.,- Just under the fianged head portion 3| of thestem are formed a fourth set of radial passages 33 Y establishing iiuid communication at all times between the bore 2l and a deliveryv fluid pressure chamberiformed in the end closure d above the sleeve valve seat. I2.

The piston sleeve valve I3 is reciprocatably slidable on the stem 30 and .has -a shortannular.'v

extension 35 projecting into the pressure charn-k ber 34.in spaced relation. thereto for seating engagement with a second coil spring 36 the oppositexendA of." thev springt beingrdis'posed for; seats* l ing engagement underthe ilangedi end of head 3|".y` The piston vsleeve valveIS has a valve'head portion V3l disposed for fluidzsealing engagement with the valve seat l2' on `thezend closure l and is movable in the :counter boredspace d by'movement of the piston sleeveA valve v,I3v to establish fluid communication between the delivery pres-` sure chamber 34and theexhaust conduit I A coil spring 38 is preferably provided andxinterposed between the underside of the valve head portion 3'I'and the inner end of the counter bore for urging the piston sleeve valve I3 toward its valve seat I2, in opposition to the pressure in thev chamber 343' effectiveon the end area of the piston sleeve valve. I3.f An O ring 39 surrounds the exterior of the pistonsleeve 'valve I3, in seal ing relation with'th'e cylindrical bore 2 Vat all times and located between the pressure iiuid delivery conduit 9 and the exhaust conduit li. A

second `O ring seal dllsurrounds the stem 30' in sealing relation with the inner surface or bore of the piston sleeve 4valve 'I3 preventing fluidA pressure leakage intermediate interior of the piston sleeve and its supporting stem 3@ at-all times. Y

In order to accelerate the release, and disengagement, of the piston sleeve valve head 3l from its seat I2 upon a raise in pressure in the pressure fluid delivery conduit 9 (and in the pressure chamber 34), in excess of the relative predetermined pressure, the valve face of the piston sleeve valve is formed with an annular groove 4I intermediate its edgesin communication with rearwardly and inwardly inclined'passages d2 leading therefrom to the space between the interior of the sleeve valve I3 and the outer surface of the piston valve stem 3i! intermediate the opposite ends of the piston sleeve valve and rearwardly of the O ring seal ring lil therefor.

While the stem 3B is actually made up of a plurality of interconnectedy sections, for convenience this part of assembly has been referred to herein as a single concentric reduced cylin drical portion or stem extending from the enlarged portion and terminating in the head 3l with the conduit 21 extending centrally through the stem to the surrounding delivery pressure chamber 34 and, of course, with the piston sleeve valve I3 slidably mounted on the stem Sil.

In order to establish, or interrupt, fluid pressure communication between the small inclined conduits 'l2 and the pressure fluid delivery conn duitl 9, intermediate the vend of the main body of the piston valve I9 and the -inner end of the piston sleeve valve I3 the stem 3% is provided with a second annular channel having an i) ring i3 therein, backed up by a serrated washer similar to the washer d4. The location of this O ring 43 on the stem 3l) is important and is disposed to enter the rear end of the bore of the piston sleeve member upon movement of the piston member I9 to the fluid delivery position, shown in Fig. l, and is moved to a vposition immediately adjacent to the .rear end of the sleeve valve when the piston valve I9 and sleeve valve I3 are in the static orr balanced position shown in Fig. 2, the O ring i3 being moved to a disengaged position by the piston valve when the piston valve is moved to its pressure relief or exhaust position, shown in Fig. 3. InA passing from the former position to the latter position, the 0 ring 43 is uncovered and the serrated back up washer d4, like thewasher 22,-perinits a pressure equalizationY under the10 ring., kpressure fluid being allowed to enter through passages 42 to the annular groove 4l in the sleeve valve face to cause a more rapid disengagement of the piston sleeve valve head 3l from its seat l2.

In order to establish pressure fluid communication between the short central conduit 23 and the longer axial conduit 2T, through the respective radial conduits 24 and 26, the wall of the casing l is formed with a conduit or conduits i5 extending parallel to the axis of the main cylinder 2 with laterally extending conduits lib and il at its opposite ends in communication with the interior of the main cylinder rlhe ends of the conduits 46 and 4"! in communication with the cylindrical bore 2 are beveled at @da and lilo: and located to register substantially in alignment with the radial passages 24 and als respectively when the piston valve le is in its pressure iiuid delivery position (as shown in Fig. l). The respective pressure uid inlet and outlet beveled ends 45a and lla are always in communication with the space between the interior of the cylinder or bore 2 and the exterior of the piston valve i9, intermediate the spaced ring seals 25 and 21 at all times.

The end closure plug 6 is formed with a central, threaded opening 49 having an 0 ring seal therein for removably mounting the s'fi pleinental or `auxiliary diierential pressure cylinde or actuator devices lil for respective actuat-..-g engagement of their piston rods with the nad si of the piston valve member iii and the ton or pistons As mentioned in the opening statement these auxiliary diiTerential pressure control devices l) are of predetermined different sizes, the proper size or capacity may be substituted, depending upon the desired predetermined difierential pressure ratio desired between the pressure iluid inlet pressure (from conduit la.) and the pressure fluid delivery pressure to the jacks iti from the delivery conduits 9a.

As best seen in Figs. l and 2 my improved valve control devices i each comprise a short cylinder c2, closed at its lower end by a cap having a central threaded shank or stem 5t which is receivable in the threaded opening lll in sealing relation with the O ring the top of the cylinder 52 being formed with a threaded central opening 55 and O ring 55 of similar dimension to the threaded opening tls and 0 ring mentioned.

When the differential pressure ratio requirement between service and delivery pressures calls for only one of the auxiliary pressure control devices El a conventional plug (such as the plug is screwed into the opening sealing the top of the required cylinder 5 l. As shown in l and 2, however', a second pressure device employed, screwed in the opening instead or" the plug and the upper end of its cylinder closed by the plug 5l. Since these auxiliary pressure devices are all substantially identical except for the operative pressure area of their operating pistons similar reference numerals will be used in the drawings. The threaded extensions or stems are each formed withan axial guide opening and sealing gaskets or O ring for slidreceiving a tubular or hollow piston rod actuator 'dil adapted to extend into the delivery pressure chamber 3d for impinging or actuating engagement with the head 3l of the piston valve Where two auxiliary cylinders are employed. the outer cylinder piston rod engages the piston of the inner auxiliary cylinder 5i. Pistons til are iixed on the other ends of the piston rods 59, closing the cylinders 52 to form the auxiliary differential pressure chambers 62 above the pistons Bil. Each cylinder 52 is vented below the piston tit, as at iis, either in the side wall or base of the cap 53. A central passage Ell extends through the piston rods 59 and pistons Si] to establish iluid pressure communication between the central passage 2'! of the piston Valve I9 and the auxiliary pressure chambers 52 in the cylinders 52. The contact or actuating ends of the hollow piston rods 5S may be serrated to allow the pressure fluids passing therein to escape laterally, for instance between their impinging ends and the contacted piston heads 3l and Eil, into the respective diierential pressure chambers 3d and 62.

In the initial operation of my improved differential pressure control device the proper size auxiliary cylinders 52 are selected for the desired diflerential delivery pressure area at the iuid delivery sides of the piston member or members @il and iii relative supply pressure area at the opposite side of the piston member i9 and then screwed in place as shown in Fig. l. The relative diameter or diameters of the cylinder or cylinders 52 as compared to the eiective diameter or pressure area oi the main cylinder 2 and piston valve l 9 as shown in the drawings is not necessarily accurately proportioned, since the drawings are primarily for illustrative purposes and the effective proportional diameters may be easily calculated by any one skilled in the art. Actually the pressure area of the pistons 59 and cylinders 52 would probably be considerably smaller, relative to the diameter of the main cylinder 2, than shown.

Referring to Fig. l, when a predetermined pressure is admitted into the supply or service pressure chamber S5, the pressure is, of course, immediately operative on the whole area of the left hand end of piston valve i9, although the pressure fluid medium passes through conduits 23, 24, d6, 35, lil, 25, 2l' and 32, out between the coils of spring 29 and into the delivery conduits and da to the respective jack or jacks l@ causing the jacks to be extended by exerting a pressure thereon proportional to the pressure in the delivery conduit and the predetermined area of the jack pistons.

The pressure fluid also passes through the conduit 2l' out of the end of piston valve i9 and lateral conduits 33 into the delivery pressure chambe- Srl, also through the conduit (or conduits) Gli into the auxiliary delivery pressure chamber (or chambers) 52 above the respective piston (or pis-- tons) @il to oppose the movement of the piston valve to the right by service pressure in chamber pressure supply chamber '55. When the predetermined delivery pressure ratio is reached in delivery pressure chamber 34, space 32a between the right hand end piston valve le and piston sleeve valve i3, and in the auxiliary delivery pressure chamber (or chambers) 62 as determined by the total operative areas thereof relative to the opposing operative area of the piston valve which is exposed to the supply pressure (and coil spring '29) the piston valve le is caused to move to the left toward the closing position as in Fig. 2. The rate of ow of the pressure fluid 'through the valve to the delivery conduit 9a is reduced as the plug valve recess Eil in the piston valve it telescopes over the plug valve i5 since the pressure fluid now entering through the slots il which are diminishing in operative area cutting .9 down the rate of'iiow. Finally whenthe static position is reached, as shown'in Fig. 2 the serrated washer 22 and its O ring 2l enters'the cylindrical valve socket 1'20 interrupting any further pressure fluid delivery to-the delivery con-Y ated in one of the connected-jack cylinders' ill, due to a partial -failure at some otherpoint in the tested structurefoverloading the jack the overload will cause a relative increase in the delivery pressure in the'connected control cylinder l, producing relatively excessive pressure inf the chambers 32d, Sil, Vandchamber orfchambers 62 depending upon how manyfofthe auxiliary differential pressure cylinders Y'tilgla etc. `are required to determine the exact pressure dierential ratio between the supply and-delivery pressures. The piston i9 will lce'inovedto the left toward the positicn-shownin'Fig. 3,' this'movement compressingthe springSB against piston sleeve valve i3. The piston sleeve valvefl 3 is normally held seated by'reason of smaller operative circumferential area at `inside of valve seat I2 and larger operative circumferential area at its opposite end exposed tothe delivery pressure.

When the piston valve I9- moves to `left it shifts the ring i3 and serrated washerlM out Aof the left hand end of rthe vpiston sleeve valve I3 and delivery pressure is lpermitted to pass longitudinally between the stem 35i-of the-piston valve and the interior of the piston sleeve valve '13, the pressure being delivered through the inclined conduits ft2 to the annular groove'fi'! in the piston valve head thus increasing theoperative delivery pressure area at the right hand end over the valve seat l2 in excess to the opposing pressure at its other end, thus this pressure and the compressed ccil spring 3s quickly move the piston sleeve valve I3 to the left to uncover the exhaust conduit 8 to the delivery pressure and ythe delivery pressure is allowed to esca-pe until it is reduced to the former predetermined pressure differential relative to the inlet pressure from `conduit l.

If the master -pressure regulating valve 'lc` is readjusted to a lower supply pressure the valves i9 and I3 are also moved ina similar manner, proportionally reducing the delivery pressure. When the supply pressure is increased the piston valve moves to right, uncovering the Apassages I1 in plug valve head `It until the pressure'ratio is again established, returning the valves again to above static `positions shown in Fig. 2. The serrated back up washer 44 is desirable to allow the pressure to escape from under theY O ring 43 and prevent the 0 ring fromjbeing blown out'of its retaining groove in the stem -3|l-whenv -it is shifted to the uncovered position bythe piston valve i9.

It is thought that the sizes of thereplacea'ble selector cylinders 52 canbe limited rto about 'three different sizes `or operative areas'and'they are indicated by'vcode numbers for-they various pres- 10 s'uresandtabulated for the `ratios of output to feed pressure. 'Y'When `the operator requires a v valve to ryield acertain predetermined pressure i which is a certainpercentage of the inlet or feed pressure, he simply locates the percentage on a tabulated table, identifies the code number of y:the auxiliary cylinder or combination of cylindersv corresponding `to the pressure, and the lcyli inders when screwed in position after the manner shown, without the use of tools, will then give vthedesired'selected .differential pressure automatically and no v`calibration or adjustment is i required.

.In the disclosed construction of the valve device the pressure of the fluid acting on the effective area of the selector-cylinder (or cylinders) will produce the for-ce that is transmitted by the piston rods 59 to the head 3| of the piston valve lg.

It is to be lclearlyunderstood that the descrip tion in the specification and drawings is by way Y cf illustration only and not to be taken in any way as limiting the spirit and sco-pe of the invention, as it is intended to 'be limited only by the terms fof the appended claims claim:

1.l In a fluid differential pressure regulator, a main casing having a cylindrical bore therethrough, a cylindrical piston valve reciprocatably mounted `within said bore, and formed with a concentric valve receiving recess in one end facing one end of the bore, a first end closure for that end of the bore having a yconcentric cylindrical Valve extension projecting therefrom into the bore adapted to seat in said cylindrical recess `upon .movement of the piston valve toward the extension, a pressure fluid supply conduit in `com-- 'munication with the interior of the bore between thesaid recessed end of the said piston valve and said `end closure member, said Vpiston valve having a concentric reduced extension projecting from its other end toward the opposite end of said bore and formed `with a head at its end, a piston sleeve lvalve reciprocata'bly mounted on said reduced extension vbetween said head and the adjacentend `of the piston valve, a second end closure'mem'ber for closing the other end of the bore lhaving a valve seat for fluid sealing engagement with said piston sleeve valve upon movement of the piston valve toward the second end closure, said casing having a pressure fluid delivery -conduit in communication with the vbore intermediate said piston sleeve valve and said piston valve and formed with a pressure fluid exhaust conduit in communi-cation with said bore intermediate said sleeve valve seat and said sec- 'ond closure, to establish communication between the vdelivery-and'exhaust conduits 'by movement of :the sleeve valve off of its valve seat, conduit meansestablishing fluid communication at all times through said rpistonvalve between the said cylindrical valve rec-ess, said pressure fluid deliveryl conduit, `and the interior of the bore between said` head and the adjacent end of piston sleeve valve, fluid sealing means between the piston sleeve valve and the bore intermediate said fluid prising a fluid pressure cylinder, a piston reciprocatable therein, actuating means operable ben tween the said piston and said 'piston valve for moving the piston valve ywithin the bore toward said first closure to seat the cylindrical valve extension in the said piston valve recess, and means establishing pressure fluid communication at all times between said pressure fluid `delivery conduit and one side of said piston for moving said piston 'toward said first closure, and venting means formed in saifd pressure cylinder intermediate the piston and said second closure for relieving the opposing pressure on said piston.

2. Apparatus as yclaimed in claim l, in which said piston sleeve valve is of the poppet type and formed with an annular channel in `its valve surface having passages leading from the inner surface of said piston sleeve valve to the said annular channel, and the sealing means between the adjacent inner surface of the piston sleeve valve and the outer surface of the piston valve extension to interrupt the fluid sealing relation of the sealing means incident to relative movement of said piston valve extension toward said iirst closure to establish fluid communication `between said 'passages in the piston sleeve valve and the said fiuid delivery conduit.

3. Apparatus as claimed in claim 1 in which said auxiliary piston valve actuating means comprises a tubular piston rod connected to the said `piston with its 'opposite end 'projecting toward said 4piston valve for actuating impingement Iwith the stop shoulder end of the piston valve, and the fluid pressure communication means includes a pressure fluid conduit through the piston and said tubular piston rod in communication at one end with said conduit means adjacent the head end of the piston valve, and at its other end with the auxiliary iiuid pressure cylinder above the piston therein.

4l. In an automatic pressure fluid pressure regulating valve structure, a casing formed with a pressure cylinder therein having a pressure fluid supply conduit adjacent one end adapted to be connected to a source of predetermined pressure, a pressure iiuid exhaust conduit connected to said cylinder at its opposite end, a pressure fluid delivery conduit connected to said cylinder intermediate said fluid delivery and exhaust conduits, a piston valve reciprocatable within said cylinder with one end thereof adapted for fluid communication with said pressure iiuid supply conduit, and its other end in communica tion with said pressure uid delivery conduit, pressure uid delivery conduit means formed in said piston valve establishing pressure fluid communication between said pressure fluid supply and delivery conduits and the ends of the piston valve, pressure fluid delivery control valve means intermediate said pressure fluid supply conduit and said piston valve pressure fluid conduit means for controlling the delivery of fluid from said pressure fluid supply conduit to said piston valve conduit means incident to variable movement of the piston valve toward the'pressure fluid supply conduit, piston sleeve valve means slidably carried on said piston valve intermediate the pressure fluid delivery conduit and said pressure uid exhaust conduit for controlling the exhaust of the pressure uid from said piston valve pressure fluid conduit means, a pressure fluid pressure chamber in said cylinder located between the end thereof and the end of the piston valve, in pressure nuid communication with said piston valve pressure fluid conduit means, spring means between the cylinder and the piston sleeve valve means for urging the piston sleeve valve means toward its seat to control pressure uid communication through said piston valve conduit means between said pressure chamber and the pressure fluid exhaust conduit, an auxiliary diiferential pressure control cylinder detachably connected to said casing in communication with said fluid pressure chamber, a piston operable within said auxiliary cylinder, a piston rod ccnnected to said piston and disposed for actuating engagement with said piston valve, said piston and rod having a pressure fluid delivery passage therethrough for establishing pressure fluid com-- munication between said auxiliary pressure cylinder above said piston and said piston valve fluid pressure chamber, resiliently yieldablc means on said piston valve between the same and the piston sleeve valve and movable by the piston valve to unseat said piston sleeve valve to establish pressure fluid communication between said pressure chamber and said pressure fluid exhaust conduit upon predetermined movement of said auxiliary cylinder piston toward said casing, spring means between said piston valve and said piston sleeve valve for yieldably urging the piston sleeve valve toward said presF sure chamber tending to unseat said piston sleeve valve incident to movement of the piston valve toward said pressure chamber, and pressure fluid sealing ring means interposed between the inner surface of the piston sleeve valve and the exterior surface of the said piston valve to prevent pressure fluid leakage between said piston sleeve valve and said piston Valves upon predetermined relative movement of the piston valve toward said pressure chamber, said ring means being movable to an inoperative non-sealing position by relative movement of the piston valve to the sleeve valve in a direction away from the pressure .chamber to establish iiuid communication between the opposite ends of the piston sleeve valve, intermediate the adjacent outer inner sin faces respectfully of said piston valve and the piston sleeve valve.l

5. In an automatic fluid pressure regulating valve structure, a casing formed with a cylinder therein having a pressure fluid supply conduit adapted to be connected at one end to e. source of predetermined service pressure, said cylinder being connected at its opposite end to a pressure iiuid exhaust conduit, and connected intermediate said pressure fluid supply and exm haust conduits to a pressure fluid delivery conduit, a piston valve reciprocatable in said cylinder having one end thereof in fluid communication with said liuid pressure supply conduit and its other end in communication with said fluid delivery conduit, pressure iiuid delivery ccndult means formed in said piston valve establishing iiuid communication between said pressure `id supply and delivery conduits and the opposite ends of the piston valve, cooperating pressure fluid delivery control valve means carried by the pressure cylinder and piston valve intermediate said pressure fluid supply to the cylinder and said piston valve conduit means for variable controlling the delivery of the pressure fluid to said piston valve conduit means incident to movement of the piston valve toward the pressure fluid supply conduit, piston sleeve valve means carried by said piston valve means intermediate the pressure fluid delivery conduit and said pressure fluid exhaust conduit for controlling the 'f-.exhaust-,of the pressure uid yfrom said piston valve pressure fluid. conduit means,y a pressure uid chamber formed in said cylinderbetween .the ends thereof vand the.l end of the piston valve,

.the cylinder and the. piston sleeve valve means .for urging the said piston sleeve valve means towardk its seat to control pressure fluid comf munication between the pressure iluidvchamber and the pressureA fluid vexhaust conduit, a differentialpressure fluid control -cylinderdetachably connected to the casing in communication with wsaid fluid pressure chamber, a piston operable vwithin said control cylinder, a tubular piston rod connected to said piston for actuating engagement thereof with the end of said piston valve, said piston and rod having a uid passage ytherethrough establishing pressure fluid coms munication between the control cylinder above said piston andsaid pressure fluid pressure chamber, resiliently yieldable means on-said piston valve between'the piston valve and said piston sleeve-valve movable by the-piston valve to uni. seat said piston sleeve valve to establish pressure fluid communication between saidpressure fluid valve and the exterior of the piston valve for -arresting fluid leakage between the interior and exterior surfaces of the said piston sleeve and piston valves upon movement of said piston valve Vtoward said pressure chamber, said pressure uid seal ring means being movable to an inoperative position by said piston valve by relative movefment of the piston valve to the piston sleeve valve away from the pressure chamber, to establish restricted fluid communication intermediate f the'opposite ends of the piston sleeve valve between the piston valve and the lpiston sleeve,

said piston sleeve valve having a plurality of small uid conduits connected vat one end between the space betweenthe piston valve and piston sleeve valve and connected at the opposite ends in communication with the valve seat en- Y gaging portion of the piston sleeve valve.

6.' An automatic fluid pressure regulating valve structure comprising a casing having a pressurecylinder therein having a pressure iluid supply conduit therefor adapted to be connected i Vat one end to a source of predetermined pressure, a pressure fluid exhaust conduit connected to-said cylinder at its opposite'end, and a presf sure fluid delivery conduit connected to said 'cylinder intermediate said pressure fluid supply 'tand exhaust conduits, a piston valve recipro- `catable in said cylinder, said cylinder having one zend. thereof: in fluid communication with said .pressure iluid supply conduit with itsother end in communication with saidpressure fluid delivery conduit, pressure fluid deliveryconduit .i means ,formed .in ksaid piston valve for establishing fluid communication through the piston valve betweeny said. pressure fluid supply and delivery :bleibetween said cylinder and said piston valve in- '.'stermediate said pressure fluid supply conduit and ll14 said piston valve pressure fluid conduit means for variable controlling thedelivery of pressure fluid from said supply conduit to saidpiston valve conduit means incident to .variable .movements of the piston valve toward thefpressure lluid suppl?,r conduit, piston sleeve valve means shiftably carried onsaid pistonvalve meansand located intermediate said pressure fluid delivery conduit andsaid pressure fluid exhaust conduit for con-- trolling the exhaust of the pressure fluid from said piston valve fluid conduit means, a fluid pressure chamber formed in saidcylinder between the end thereof and said exhaust conduit and the adjacent end of .the pistonvalvain communication with said piston` valveconduit means,

spring means between the .cylinder and the sleeve valve means for urging. said piston'sleeve valve means toward itsseat within the cylinder to control fluid pressure communication between the fluid pressure chamberand the .pressure fluid enhaust conduit, an auxiliaryfdiiferential pressure control cylinder connected'tozsaid fluid pressure chamber, a piston operable within said auxiliary cylinder', a piston rod connected to said piston and extending toward .said piston-valve for actuating engagement with the end of said piston valve, said piston and rod having a pressure fluid delivery passage therethrough for establishing fluid communication between' the auxiliary cylinder above the header saidupiston and said fluid pressure chamber, resilient yieldable abutment means carried on saidpiston valve between said piston valve and rsaid piston sleeve valve and movable with the piston valve tending to unseat said piston sleevevalve to establish fluid communication between said pressure chamber and said exhaust conduit upon movement of said auxiliary cylinder pistony ina direction toward said piston valve, spring means between said piston valve and the piston sleeve valve for yieldably stressing the piston sleeve valve toward said pressure chamber incident .to"movement of the piston valve in a direction toward said pressure chamber, a pressure uid seal .interposed between the interior of the piston sleeve valve and the exterior of the piston valve .for arresting pressure fluid leakage between the piston sleeve valve and piston valve upon movement of the piston valve toward said pressure chamber and movable to an inoperative position by relative movement of the piston valve tozthe sleeve valve in a direction away from the pressure chamber to establish fluid communication. intermediate the opposite ends of the .piston sleeve valve between the piston valve andthe piston sleeve valve, said piston sleeve valve having a plurality of small fluid conduits formed' therein, each in communication at one'end with the space between the piston valve and piston sleeve valve with their opposite ends opening through the valve seat engaging portion in communication with the outlets of said plurality of small fluid conduits.

7. In a fluid pressure regulator device, a main cylinder having a bore therethrough, a first closure for one end thereof, an Y,adjustable elongated support extending from said ,first closure axially into said onelendof the bore, a second closure for 'the other end of the bore having an axial opening therethrough-into said bore, a plurality of/pressure regulatorcylinders of predetermined diameters adapted to be removably secured to said second closure, -each pressure regulator cylinder having an-axial guide opening therein in communication with saidrbore through the second closure, a piston slidable in A ch oi said pressure regulator cylinders, pls'tc each having a tubular piston rod slidable in sa guide opening, one of said tubular piston being adapted to extend into said` ogs, sai

rods having a pressure fluid conduit axially therethrough to establish presu communication between the bore and L 5s cylinders above the pistons, vent in each of said pressure regulator cylinders below said pistons, a plug valve head carried on the inner end of said elongated support, a piston valve member axially slidable in one di; 'on in said bore toward said first closure and in the opposite direction toward the second piston valve having a valve seat therein comprism ing valve receiving recess for receiving said valve therein upon predetermined. mov the piston valve toward said first piston valve having a reduced opposite end terminating in a later Y 'fog ing stop shoulder and spring seat, a val member surrounding said piston valve z and freely reciprocatable thereon 'a piston valve and the stop shoulder formed 25 with an annular valve head facing the second closure, spring means between said stop shoulder and said sleeve valve head for urging the sleeve valve toward said piston valve, a second spring means between said piston sleeve valve and said piston valve for urging said piston sleeve valve toward said stop shoulder, said second closure having a valve seat facing the piston sleeve valve for cooperating pressure scaling cngag'ernent therewith upon movement or" the piston sleeve and piston valves toward said second closure, spring means in bore between sleeve valve and said main cylinder for urging said piston sleeve valve toward seating eng-aga with the second closunv valve a pressure supply conduit forr d in main cylinder in communication w li said bore between said rst closure and the recessed valve receiving end of the piston va ve, a pressure delivery conduit formed in said main cylinder in 45 communication with said bore between the piston valve and the piston sleeve valve, a pi e uuid exhaust conduit formed in said main cylinder in communication with said 1core between sa pressure fluid delivery conduit and said second sure valve seat adjacent said second closvh l. .le seat, conduit means form-cd the piston valve and said piston valve extension ing fluid communication at all th the interior of the cylindrical plug valve recess in the piston valve, and the space between the reduced extension end of the piston valve 'and the piston sleeve valve, and between stop shoulder end of the piston valve and said second end closure for establishingfluid conununicaticn 00 at all times between the pressure iiuid lelivery conduit and the interior of the plug valve r cess and the space between the second end ciosuA above the valve seat therein at all a seal surrounding said piston valve between sai l pressure supply and delivery conduits, and a ilu seal surrounding said piston valve between said es between pressure delivery conduit and said exhaust conduit.

P' 8. in apparatus as claimed 1n claun 1n which l ranged to be uncovered by movement of the sleeve 75 valve toward the said stop shoulder to establish fluid communication between the space between the interior of the sleeve valve and the exterior of the extension, an annular channel surrounding 'the sleeve valve and formed in the valve seat portion thereof, and a pressure fluid supply conn duit in the sleeve valve connected between said annular channel and the last mentioned space.

9. Apparatus as claimed in claim 7 in which said plug valve is slotted longitudinally at its outer end to provide a variable fluil delivery opening between pressure 'fluid supply conduit and the interior of the sleeve valve recess as the piston 'valve is shifted to cause the plug valve to progressively enter the valve recess in the piston valve.

10. Apparatus as claimed in claim 7 in which the plug valve fluid sealing means comprises an G ring seat formed in the periphery of said plug valve, a resilient O ring in said seat and a serrated baci: up washer interposed in the seat between one end of the seat for the O ring and the O ring, to permit fluid pressure to pass under the O ring from the plug valve recess upon com-- plete disengagement of O ring from its sealing relation with the interior of the plug valve recess surface.

1l. Apparatus as claimed in claim 'l in which the seal between the piston sleeve valve and the piston valve extension includes an O ring, an annular recess formed in and surrounding the piston valve extension for receiving the o ring therein, and a serrated spacing washer between the O ring and the side wall of the recess for allowing fluid pressure to pass under the o ring before the said O ring is completely uncovered by the relative movement oi the sleeve valve on the extension toward the second closure.

l2. in a dilerential pressure control valve device, a casing having a main pressure cylinder therein closed at its ends, having a pressure fluid supply conduit in communication with the cylinadiacent one end, a pressure fluid exhaust conduit in communication at the other end, and a differential pressure delivery conduit in comlriunication adjacent said other end between the supply and exhaust conduits, an adjustable plug valve support extending into said one end of the cylinder, valve means nXed on the end of the support concentrically within the cylinder adjacent the supply conduit comprising a cylindrical lug valve head, an annular channel surrounding support below said head, a resilient O ring seal positioned in said channel, a serrated flat metallic washer positioned in said channel between the head and the O ring, a piston valve reciprocatable within said cylinder having a cylindrical recess in one end for receiving said plug valve head and said 0 ring ytherein upon pren determined piston valve travel toward said pressure supply conduit, said piston valve having pressure duid conduit means formed therein in communication vat one with the interior of said recess and at its opposite end with the space between the said other end of the cylinder the other end of the piston valve and including a connected conduit through said piston valve in communication with said delivery conduit, a pisn sleeve valve reciprocatable on the piston valve etween said delivery and exhaust conduits having a valve head facing said other end of the cylinder, a cooperating valve seat in said cylinder for said piston sleeve valve head, located between said pressure delivery conduit and said exhaust conduit, spring means operable between the casing 17 andsaid pistonsleeve valve. for urging ,Said piston sleeve valve toward said cooperating seatresi' ,t abutment meansv on said pistonfvalVS'fOr url st. ig engagement with the piston sleeve valve upon predetermined movement of the piston valve toward. said supply conduit, fluid'sealing means between said piston valve and the cylinder intermediate said Supplyk and delivery. conduits, fluidy Stalling means intermediate said piston valve and said piston sleeve valve, fluid sealing means between `said piston sleeve valve and said cylinder, intermediate said delivery and exhaust conduits, pressure actuated means for moving said piston valve tow d said pressure supply conduitcomprising an auxiliary pressure cylinder removably carried by casing, a piston therein, piston valve 'actuating means operable between said piston and said DiS- ton valve for moving the piston valve toward said fluid pressure supply conduit, and a pressure supply conduit means connected in communication with said main pressure-chamber between the interior of the main pressure cylinder inter-me.- diate said plug valve recess in the piston valve and the space above piston in the auxiliary pressure cylinder, and a venting passage formed in said auxiliary cylinder below said piston therein.

13. Apparatus as claimed in claim 12 in which the auxiliary pressure cylinder has a predetermined diameter relative to the diameter of the main cylinder, for the effecting a predetermined pressure differential between the pressure supply and delivery conduits, whereby auxiliary cylinders of different diameters can be substituted for varying the pressure differential between said supply and delivery conduits.

14. Apparatus as claimed in claim 13, in which a second auxiliary pressure differential actuator is provided, including a second auxiliary pressure cylinder removably connected in concentric alignment on the rst auxiliary pressure cylinder and said piston, a piston movable in said second auxiliary cylinder having a piston rod projecting therefrom into the first auxiliary cylinder for actuating engagement with the first auxiliary piston, a pressure fluid conduit formed through said second piston rod and piston in communication at one end with the first auxiliary pressure cylinder above the piston therein and with the second auxiliary pressure cylinder above the piston therein, said second auxiliary cylinder being vented below the piston therein, whereby the fluid delivery pressure in the main cylinder is in communication with both of the auxiliary cylinders above the pistons therein, in opposition to the presure on the piston valve in the main cylinder adjacent the pressure supply conduit.

15. Apparatus as claimed in claim 12 in which said auxiliary pressure actuated means comprises an auxiliary pressure cylinder removably disposed on the casing in concentric alignment with said piston valve, a piston in said auxiliary cylinder having a piston rod therefor projecting through the end of the main cylinder into actuating engagement with the end of the piston valve and formed with a fluid conduit through said piston rod and piston to establish pressure iiuid communication between the interior of the main cylinder and the interior of the auxiliary cylinder above the piston, said auxiliary cylinder being vented below the piston therein.

16. A differential pressure control valve device, a main cylinder, a piston valve operable within the cylinder, a pressure supply conduit connected to said main cylinder at one end at one side of the piston valve, an exhaust conduit connected to the main'cylinder at its opposite end, a diiferential' pressure deliveryl conduit con-S therein establishin'gfluid communication at said one end with said pressure supplycendu-it and at its other end withsaidf-pressure chamber, and a connected conduit in communication with the cylinderjbetween said piston sleeve yvalve and said delivery conduit, ,adjustable valve and cooperating seat means between4 'said piston valve and said onef end of the cylinder intermediate said pressure supply and Ysaid'conduit means, operable to regulate the passage of fluid to said conduit means incident to predetermined movement of said piston valve toward said one end of the cylinder, spring means between said piston sleeve valve and said cylinder for resiliently urging said piston sleeve valve toward said pressure chamber and toward seating engagement with said cooperating valve seat, spring means between said piston valve and said piston sleeve valve urging said piston sleeve valve toward said valve seat upon piston valve movement toward said pressure chamber, resilient abutment means between said piston valve and said piston sleeve valve for unseating said piston sleeve valve incident to predetermined piston valve movement toward said one end of the cylinder, and auxiliary pressure actuating means for moving said piston valve toward said one end of the cylinder comprising an auxiliary pressure cylinder, means removably mounting said cylinder on said other end of the main cylinder, a piston shiftable within said auxiliary cylinder, actuating means between said piston and said piston valve for shifting the piston valve toward said one end of the main cylinder, and pressure conduit means in communication between the auxiliary pressure cylinder at the other side of the said piston and the said main cylinder pressure chamber.

17. Apparatus as claimed in claim 16 in which said piston sleeve valve is formed with a plurality of uid supply conduits leading from its valve face the interior of the piston sleeve valve intermediate its ends, a pressure seal interposed between the interior of the piston sleeve valve and the exterior of the piston valve intermediate said passages and said piston sleeve valve and remote from its valve face, movable by said piston valve to unsealing relation, incident to movement of the piston valve in said piston sleeve valve toward said one end of the main cylinder to admit delivery pressure to said valve seat to assist in unseating said piston sleeve valve to establish fluid communication between the said pressure chamber and said exhaust conduit.

18. Apparatus as claimed in claim 1'7 in which the said other end of the main cylinder is formed with an axially threaded opening therethrough, and said auxiliary pressure cylinder is formed with a threaded axially nipple receivable in said threaded opening, said nipple having an axial guide opening therethrough, said auxiliary cylinder having a removable centrally threaded c10- 19 sure at its other end, and forming an auxiliary pressure chamber, a piston reciprocatable within said auxiliary cylinder having a hollow piston rod extending therefrom through said guide opening adapted to project into said pressure chamber of the main cylinder for actuating engagement with the end of said piston valve and establish pressure communication between said main cylinder pressure chamber and said auxiliary cylinder pressure chamber, said auxiliary pressure chamber having a pressure venting conduit located between piston therein and the guide passage for relieving fluid pressure in the auxiliary chamber below the said piston.

19. Apparatus as claimed in claim 18 in which a second auxiliary pressure cylinder is provided, having a threaded axial nipple received in the threaded opening for the plug closure of the iirst auxiliary cylinder and formed with an axial guide opening therethrough, said second auxiliary pressure cylinder having a threaded opening in its opposite end, and an axial closure received in the last mentioned threaded opening to form a second auxiliary pressure chamber, a piston reciprocatable Within said second auxiliary cylinder having a hollow piston rod projecting therefrom through the last mentioned guide opening adapted to extend into the first auxiliary cylinder pressure chamber for actuating engagement with the rst auxiliary cylinder piston, for moving the same toward said piston valve, the passage through said last mentioned hollow piston rod being adapted to establishing iiuid communication through the first mentioned auxiliary cylinder piston rod between the main cylinder pressure chamber and the second auxiliary cylinder pressure chamber above the piston therein.

References Cited in the le of this patent UNITED STATES PATENTS Number' Name Date 2,496,577 Cahill Feb. 7, 1950 2,500,555 Majneri Mar. 14, 1950 2,656,846 Anderson Oct. 27, 1953 

